Capturing a glycosylase reaction intermediate in DNA repair by freeze-trapping of a pH-responsive hOGG1 mutant.

ABSTRACT: The human 8-oxoguanine DNA glycosylase 1 (hOGG1) is a bifunctional DNA repair enzyme that possesses both glycosylase and AP-lyase activity. Its AP-lyase reaction mechanism had been revealed by crystallographic capturing of the intermediate adduct. However, no intermediate within the glycosylase reaction was reported to date and the relevant reaction mechanism thus remained unresolved. In this work, we studied the glycosylase reaction of hOGG1 by time-resolved crystallography and spectroscopic/enzymological analyses. To trigger the glycosylase reaction within a crystal, we created a pH-responsive mutant of hOGG1 in which lysine 249 (K249) has been replaced by histidine (H), and designated hOGG1(K249H). Using hOGG1(K249H), a reactive intermediate state of the hOGG1(K249H)-DNA complex was cap

SUBMITTER: Unno M 

PROVIDER: S-EPMC12318605 | biostudies-literature | 2025 Jul

REPOSITORIES: biostudies-literature